Self-driving vehicles have been expected to bring all kinds of futuristic benefits, including smarter cities and safer streets and highways.

But some U.K. researchers have identified a potentially more risqué repercussion of the autonomous vehicle revolution: more sex in cars since no one has to be behind the wheel.

More than a dozen automakers and companies such as Uber, Lyft and Alphabet's self-driving car company Waymo have been testing autonomous vehicles.

While some accidents have slowed those tests, overall safety is expected to be enhanced with autonomous net-connected vehicles, with researchers estimating up to 90 percent of traffic accidents could be avoided, U.K. researchers Scott Cohen, a tourism and transport professor at the University of Surrey, and Debbie Hopkins, a geography and environmental researcher University of Oxford, write in the Annals of Tourism Research.

Autonomous vehicles are expected to be widely available by 2025 and, the most optimistic forecasts indicate, the primary means of car transportation globally, they say. But little research has focused on how self-driving vehicles might change tourism and night life, Cohen and Hopkins say in their research paper in the January 2019 issue.

"To date, such thinking has been limited to everyday – and day-time – mobilities," they write. "Tourism and leisure users have, however, been some of the first to experience automated vehicle technologies. Future thinking needs to diversify into the broader suite of (potential) users, and temporalities."

Some basic benefits self-driving vehicles would provide include helping travelers avoid driving when they're tired or unfamiliar with their travel destinations or local driving rules. Tourists could focus on sightseeing, rather than "the task of driving," they say.

But sex and prostitution could become "a growing phenomenon" in autonomous vehicles, they suggest. Shared self-driving vehicles such as taxis or ride-sharing cars "will likely be monitored to deter passengers having sex or using drugs in them," they write. But riders could find ways to disable such monitoring, and privately-owned self-driving vehicles "will likely be immune from such surveillance," they write.

"Such private (connected and autonomous vehicles) may also be put to commercial use, as it is just a small leap to imagine Amsterdam’s Red Light District ‘on the move'," they write.

Similarly, restaurants may face competition from "moving restaurants" and hotels with "moving motels," they say. These potentially "far-reaching implications" require further study, the researchers say.